Energy efficiency has important impact on both economics of operating costs and carbon dioxide “CO2” emissions. The production of power from hydrocarbon fuels and from geothermal thermal sources are individually known in the art. The combustion of fuels, whether it be hydrocarbons, biomass, biofuels, or coal as known in the art yields CO2 emissions. It is known in the art that these CO2 emissions can reach elevated pressures as sufficient for injection into a geothermal injection well by a wide range of compressors, pumps, etc. as known in the art. One such source of carbon dioxide is the combustion of coal or hydrocarbons for a wide range of applications ranging from dedicated power generation systems to industrial processes.
Traditional power generation cycles using supercritical carbon dioxide “ScCO2” have distinct challenges associated with at least one of CO2 leakage from the otherwise closed loop cycle, and the direct impact of CO2 within the high pressure side of the closed loop cycle on the low pressure side of the closed loop cycle and vice versa.
Traditional power generation cycles using ScCO2 heated by a geothermal source such that the ScCO2 is the working fluid in the power generation cycle and a geothermal heat transfer fluid is the fluid extracting thermal energy from the geothermal source are both known in the art. Additionally, the use of ScCO2 as both the working fluid in the power generation cycle and the geothermal heat transfer fluid (i.e., the “same” ScCO2 is used for both) is also known in the art.
The combined limitations of existing power generation systems utilizing ScCO2 as the working fluid include, though not limited to, CO2 leaks, insufficient high-side temperature (i.e., insufficiently high geothermal source temperatures), or fluid components or combustion byproducts of those fluid components that are concurrently extracted from the geothermal extraction well that are condensed within the power generation expander.